1. Field of the Invention
The present invention relates to air assist fuel injection systems and, more particularly, to covers for fuel pressure regulators of air assist fuel injection systems.
2. Description of the Related Art
Conventional fuel injectors are configured to deliver a quantity of fuel to a combustion cylinder of an engine. To increase combustion efficiency and decrease pollutants, it is desirable to atomize the delivered fuel. Generally speaking, atomization of fuel can be achieved by supplying high pressure fuel to conventional fuel injectors, or atomizing low pressure fuel with pressurized gas, i.e., xe2x80x9cair assist fuel injection.xe2x80x9d
Conventional air assist fuel injectors are typically located in the head of an engine and are adjacent a rail that houses a conventional fuel injector and also defines a mount for the air assist fuel injector. The conventional fuel injector and the rail are configured such that a metered quantity of fuel is delivered from the fuel injector directly to the air assist fuel injector. Additionally, the rail includes a number of passageways that deliver pressurized air to the air assist fuel injector. The air assist fuel injector atomizes the low pressure fuel with the pressurized air and conveys the air and fuel mixture to the combustion chamber of the engine.
A conventional air assist fuel injection system typically includes a fuel pressure regulator, such as a diaphragm or differential pressure regulator, which generally maintains the fuel supply pressure at an acceptable level so that proper fuel flow characteristics to and through the injectors is assured. In the conventional configuration, the fuel pressure regulator maintains this fuel pressure at the desired limit by maintaining a pressure differential between the fuel supply pressure and a reference pressure, such as the air supply pressure to the air assist fuel injector. The fuel pressure regulator is typically mounted on the rail of the air assist fuel injection system, and an array of external conduits typically communicate the pressurized air and pressurized fuel from the rail to the fuel pressure regulator so that the fuel pressure regulator can maintain the aforementioned pressure differential.
The conduits that communicate the pressurized air to the fuel pressure regulator typically include exposed or external hoses and connectors, which are susceptible to damage during operation of the engine, especially during high temperature and pressure conditions. These exposed hoses and connectors also complicate the assembly of the air assist fuel injection system and are not well suited for various space-constrained engine configurations.
In light of the previously described problems associated with supplying air and fuel to the fuel pressure regulators of air assist fuel injection systems, one object of the embodiments of the present invention is to provide a cover that covers a fuel pressure regulator and is configured to supply pressurized gas to the fuel pressure regulator, preferably without external hoses and connectors.
Other objects, advantages and features associated with the embodiments of the present invention will become more readily apparent to those skilled in the art from the following detailed description. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modification in various obvious aspects, all without departing from the invention. Accordingly, the drawings and the description are to be regarded as illustrative in nature, and not limitative.